1. Field of the Invention
The present invention relates to an optical scanner and, more particularly, to an optical scanner using a laser beam for scanning.
2. Related Art
A prior art laser scanner incorporated into office automation equipment, such as a laser printer or a laser facsimile terminal equipment, a laser plotter, a laser inspection device or the like comprises, in combination, a polygonal rotating mirror and an f-.theta. lens. This prior art laser scanner, however, has disadvantages in that the polygonal rotating mirror must be fabricated with high accuracy and the f-.theta. lens consisting of a plurality of lenses is expensive, and hence it is difficult to reduce the cost of the laser scanner. On the other hand, since replicas of a hologram can be produced by mass production, the hologram scanner can be manufactured at a relatively low cost.